| 摘要 |
A loss of light (LOL) indicator for an optical network comprises a micro-electro-mechanical systems (MEMS) optical switch and a light detector. A light signal transmitted along a light path into the optical switch suffers attenuation in passing through the switch, e.g. through dispersion. The light detector is positioned such that the attenuated light is detected in order that a loss of light signal is generated if no light is detected, but with substantially no increase in the overall attenuation of the optical switch. In one embodiment incoming light is switched to output ports 10 using a mirror array and detector diodes 9 are distributed around the output ports to detect dispersed light. In an alternative embodiment diodes 12 are placed behind the mirror array 5 to detect light which has not been reflected by the mirror. |
